Challenge: Battery Charging in a third world country

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Amayumi
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Challenge: Battery Charging in a third world country

Dear sirs,

I am experiencing some difficulties to find the information below, so I came here to ask some help.

I live in Brasil and since we are a third world country, we doesn’t have access to many USA products because of high custom taxes.

I use a deep cycle battery to operate my boat fishing ligths.

The very best bang for the buck option around here is a locally made, Johnson controls battery called heliar, model freedom

(https://www.johnsoncontrols.com/batteries/lead-acid-batteries/battery-br...)

It is a stationary, deep cycle, maintenance free (kind of sealed), 12V, lead acid, flooded battery.

(Other technologies, as lipo, lion, agm, etc are waaay pricier around here)

So I need a proper charger for my lead acid battery, to make it last longer, and avoid to charge it from car alternator.

After lots of homework and manual readings, I found that my lead acid battery need a charger that gave me, at same time:

A) 3 stages: charge, equalization and floating modes.

B) specific Charging and Equalization tension: 14,4 a 15,5 V @ 77°F

C) specific Floating tension : 13,2 to 13,8 V at 77°F

D) temperature compensation:
For each 33.8°F above acima de 77°F, subtract 0,033 V
And
For each 33.8°F below 77°F, add
0,033 V

E) specific for flooded lead acid battery

F) smart, so I could left the battery Charging unnatendend for weeks.

H) I could not find the best amp/hour charging rate for it , but I presume the lower the best. I wont need to recharge it fast since I will use it just 1x a week .

After some research, it seems that a “minn kota precision battery charger” meets all this spec needs and because of this, it would be a no brainer option (I’m no seller, just specs at
(https://minnkotamotors.johnsonoutdoors.com/battery-chargers/board-precis...)

MY PROBLEM:

The “minn kota battery charger” is not cheap inside my country.

And if I try to import it from USA, the custom taxes would doubles its price (plus shipping cost..x3 or x4).

So, I imagine that this charger must have lower price competitors, more affordable to import, but with the same quality and needed features.

After all, should exists other good brands in USA.

So, I came here to ask if anyone could help me, pointing some charger models that meet all my battery needs (above), being not so hard on my wallet.

Would anyone reccomend a cheap, smart, lead acid battery charger?

I use to buy from eBay, but I can order from any other vendor.

I just need to know other brands/models that offers the same specs and well know quality for less money .

And I hope you guys would known it.
Would any please help me?

Thanks a lot

Cheers from Brazil

e1000
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What about a NOCO or CTEK?

Examples are NOCO G3500 or CTEK MXS 5.0

Lightbringer
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Wow, that’s quite the wish-list… Big Smile

I was always happy with “topping off” Pb-acid batteries with a cheapo float-charger. Its inherent internal resistance would be enough to control (more or less) the float-voltage to what the battery itself wants to draw.

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Pete7874
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Lightbringer
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Ah, that NOCO was the one I was thinking about. I know someone who RVs a lot, and he had a NOCO, if I’m not mistaken.

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e1000
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Lightbringer wrote:
Wow, that’s quite the wish-list… Big Smile

I was always happy with “topping off” Pb-acid batteries with a cheapo float-charger. Its inherent internal resistance would be enough to control (more or less) the float-voltage to what the battery itself wants to draw.

Agree, I think he’s over-thinking it. Could probably get away with a cheapo car battery charger, but if he’s that worried, the nice ones (NOCO, CTEK) aren’t terribly more expensive.

Amayumi
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Hi, all!

Thanks for sharing your knowledge and advices!
I will try the recommended ones!

I have noticed that this chargers do inform its charging current in amperes.

But most battery brands do not inform the recommended charging rates for its batteries.

Can I assume (if I am not in hurry to recharge ) that the lower the charging current the best?

I am asking because I read that lead acid batteries should be charged with anything from c/5 (max) to c/10 (min), Wich means capacity in ah divided by 5 or 10.

But the above recommended models charge with even lower currents, even with 1 amper (even lower than c10, above).

Should I understand that (if I m not in a hurry) the charger could (should?) operate with as low current as possible? (Let’s say 1 amper or less?)

Or each lead acid has a specific optimal charging current and I must select the charger that offers it?

Thanks!

Pete7874
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Amayumi wrote:
I am asking because I read that lead acid batteries should be charged with anything from c/5 (max) to c/10 (min), Wich means capacity in ah divided by 5 or 10.

What is the capacity of your battery?
Amayumi
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Pete7874 wrote:
Amayumi wrote:
I am asking because I read that lead acid batteries should be charged with anything from c/5 (max) to c/10 (min), Wich means capacity in ah divided by 5 or 10.
What is the capacity of your battery?

54 ah(10hs)
60 ah(20hs)
70 ah(70hs)

244mmx175mmx175mm
14.7kg

Float charge
13.2 – 13.8 @25°c

Equalization charge
14.4 – 15.5 @ 25°c

Lexel
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I got a CTEC for years and it works great